The present invention concerns a vaporisation injector suitable for operating in a gas chromatography instrument.
The injector is a device which allows the transfer of a sample, consisting of the substance to be analysed and a solvent, for example from a syringe to the gas chromatography column by means of a carrier gas. The injectors can be on-column injectors, when the sample is injected into the column in a liquid form and vaporises at the beginning of the column, or they can be vaporisation injectors, in which case the sample is heated and vaporised inside the injector.
The subject of the present invention is a vaporisation injector, generally consisting of a heated vaporisation chamber into which the sample is fed for example via the needle of a syringe which crosses an insulation septum.
From the vaporisation chamber, the vaporised sample is transferred to the column by the action of the carrier gas, said transfer being performed on the whole sample injected (splitless), or only on a fraction of the sample injected (split). In the latter case the main part of the sample is diverted and discharged together with a fraction of the carrier gas. Furthermore, a current of the carrier gas is diverted before it meets the sample, in order to purge the septum.